This photoelectric circuit was found in a 70’s Ferranti's documentation. The circuit uses an operational one from that time. Modern equivalent components can be used in a new project.
Suggested by General Electric this circuit has 3 control positions for one load. The diode is...
This circuit was found in a 90's Electronic Design. It takes advantage of the nonlinearity...
With this circuit from Popular Electronics it is possible to determine the characteristics of a microammeter...